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rockclimber412
Aug 17, 2003, 11:10 PM
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what is a good lenth to cut your webbing into to make a good three point anchor system for top-roping, also how many feet of webbing do i need, i have thirty feet of 1 inch tubular so far.
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rockzen
Aug 18, 2003, 12:39 AM
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Are you talking TR anchors? If so, it depends on how far away the anchors are.
RockZen
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gene
Aug 18, 2003, 12:49 AM
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I personally would suggest buying 2 or 3 more pieces of 30-40 ft webbing. Lots of times you'll have to set up toprope anchors from stuff like tree's back away from the cliff edge, so you need LONG stuff to let the biners for the rope hang free over the edge. At times like this you'll need more than one length of webbing, so that you can hook to more than one tree/object if possible to be redundant.
webbing is cheap (20-30 cents a foot), and when you daisy-chain it up, a 30-ft piece of webbing is only 1-2 ft long, so packs easy without getting tangled up into everything else in your pack.
Just be redundant & double-check your set-up...... if Bob Vila were a climber, his motto would be "Check twice - die once"
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fear
Aug 18, 2003, 1:57 AM
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If you've got the money, screw the webbing and get yourself a thick 60m static rope. It'll last a lot longer and be useful for plenty of other things... Still pad the edges.
You also really only need two bomber anchors for a TR, not that 3 or more is a bad thing if you're new and just figuring things out......
-Fear
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emtclimber
Aug 18, 2003, 5:52 AM
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It really depends on what your anchoring to, bolts close to the edge or trees 15-20 ft from the edge, are you climbing in the same spot all the time or TR'ing in various spots? Make your decision based on that. I agree with fear...you only need 2 bomber anchors for TR and make sure you protect your rope/ webbing from sharp edges while TR'ing.
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philbox
Moderator
Aug 18, 2003, 6:01 AM
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Yup, I`d agree, toss the webbing and use the static rope for set ups for toproping. If you are wanting something for multipitch lead anchors then grab yourself a webolette.
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ptone
Aug 18, 2003, 6:11 AM
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Man, it totally depends on the situation. The most important factor (besides that the placements etc are good) is the angle of the sling/web(cord)olettes.
If the placements or anchor points are far apart, and you use short slings, then the angle of the attachments are wide, an you can have a "gear" effect, where the shock load on the anchors can be increased rather than decreased!!!
Tho it's best to learn from others in real situations, the book on anchors by John Long, and/or the book Mountaineering, Freedom of the Hills (as well as others I'm sure) have great sections on anchor equalization and set-up, on how the angle of the slings from each of the placements to the anchor point effects the shock load and pressure on each of the placements. And of course you want your slings long enough to ensure that only static material (web/cord) lies over edges, dropping the biners into clear space...
This is the info that is the best for determining how long your slings/web- or cordolettes etc should be, and it depends on the climb.
Don't take it from me, read up, then get a partner in the field to play and practice with when you are climbing!
Peace,
p
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ptone
Aug 20, 2003, 6:28 AM
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Don't know if you're still following this, but I just happened to be leafing thru Mountaineering Freedom... and saw this table, thought I'd pass it along:
The 'Angle' they refer to is the 'V' angle formed between two anchor points and the rope hang point (focal point). The larger the number of degrees, the wider the anchor points are, ie the wider the 'V' that is formed is.
The 'Force' is the percentage of the shock weight on each individual anchor point.
Angle degrees Force on each anchor
0 (looks like an I) 50%
60 (like thin V) 60%
90 (a right or square angle) 70%
120 (wide V) 100% (like going off of one anchor)
150 (very wide V) 190% (Almost double the force on a single anchor)
170 (almost a line) 580% (like you and six friends on a single anchor point)
A badly set 2 point anchor can increase the shock load, making it worse than going off of a single anchor point!!!
Just a thought.
peace
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phyreman
Aug 22, 2003, 11:57 PM
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As some people said above it totally depends on what you're anchoring to. I have had pretty good luck with carrying 2 25' pieces, a 40' peice, and a couple each of 24", 36", and 48" spectra slings.
Because there are factors to setting up anchors not immediately obvious (such as the previously mentioned fact that wider angles significantly increase the forces), you should really spend some time with someone that knows what they're doing when setting up anchors. If you don't have that opportunity, Mountaineering: Freedom of the Hills, John Long's book, or On Rope are all excellent. If you're short on money check for used copies on Half.com or Amazon's used books. If you've never read up on anchors you will learn a ton of stuff.
Nate
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tenn_dawg
Aug 24, 2003, 1:30 AM
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In reply to: Don't know if you're still following this, but I just happened to be leafing thru Mountaineering Freedom... and saw this table, thought I'd pass it along: The 'Angle' they refer to is the 'V' angle formed between two anchor points and the rope hang point (focal point). The larger the number of degrees, the wider the anchor points are, ie the wider the 'V' that is formed is. The 'Force' is the percentage of the shock weight on each individual anchor point. Angle degrees Force on each anchor 0 (looks like an I) 50% 60 (like thin V) 60% 90 (a right or square angle) 70% 120 (wide V) 100% (like going off of one anchor) 150 (very wide V) 190% (Almost double the force on a single anchor) 170 (almost a line) 580% (like you and six friends on a single anchor point) A badly set 2 point anchor can increase the shock load, making it worse than going off of a single anchor point!!! Just a thought. peace
A while back, jt512 (the smart bastard) figured out the formula for calculating force felt by each anchor with regards to the angle of the anchor connection. We were discussing the force felt by slackline anchors when It came up.
I'll post a link in a moment...
Travis
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soccer_fan
Aug 24, 2003, 3:07 AM
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I've got 40' of 1" webbing, and in AR so far its been all I've needed save once, had to extend part of it with 2' runners b/c I went around two trees and the 'biners didn't drop nicely over the edge. I've got a few (3) 4' runners just in case, and several trad draws that I use with lockers to set up on routes with bolted top-anchors.
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socalclimber
Aug 24, 2003, 2:48 PM
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Screw the webbing. Fear is right on the money. Go get yourself 40' to 50' feet of 10mil or larger static. It will last for ever, and is very strong. As far as anchors go, minimum 3 pieces. Top rope setups are largely unattended. Meaning people set them up and ignore them after that. Telling a beginner that 2 pieces will suffice is just plain old insane. Use 4 or 5 pieces if you have to. I have seen unattended anchors poorly rigged where one or more pieces have become useless and nobody notices. You wouldn't believe some of the stuff I have seen on top of the crags in Josh.
I guide down here in Josh and teach beginners courses. I would never tell a beginner that you only need 2 pieces to construct an anchor. Make the anchor overkill. In time, as you gain experience, you will begin to figure out what good anchor is vs. a bad one.
Get yourself 150' of static, cut it into 3 sections. Now you have MORE than enough rigging material. You will be using for years to come. Granted it's more expensive than webbing, but you won't be replacing it anytime soon.
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thomaskeefer
Aug 24, 2003, 3:20 PM
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About using static for your anchors.. (I dont have this setup myself because I can get 1" webbing for free :) but not static line)
A really slick looking way to pad the edges is to pad the rope instead. I think that fish products has something on their site for the purpose but a 6 foot piece of tubular 1" that you slide over the static rope works really well. You just burn the ends of the tubular so that they are not sealed then you can basically make this a tube to slide the static anchoring line through. After you set your anchor just slid the 1" down the rope to the spot where it goes over the lip.. and it is easy to replace when it starts to wear out.
hope that helps
tom
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ptone
Aug 31, 2003, 2:39 AM
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I saw that somewhere too--It's a great trick to reduce wear on the sheath.
Just a note cause I didn't see it above, and it's a beginner thread--
Note that when they talk about rope vs webbing for anchors it's always staticrope. Regular climbing ropes are dynamic, meaning they have some stretch (this is what saves your ass in a fall). Do not use this for anchors. When you move your weight (fall, sit or lower or whatever, even on top rope) the rope stretches, and rubs. Even with the nifty rope protector above, this is trouble. A rope can melt rubbing against itself or webbing as quick or quicker than rock will wear it thru. (eg the rope inside the protecto-web tube).
Static for anchors etc, dynamic for climbing.
Just a thought.
peace,
-p
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boz
Sep 1, 2003, 5:29 PM
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Webbing is nice for certain applications, (for example mine, at a scout camp, where we need to set up 4 or more climbs up at the same time, and fast).
It's easy as all hell to use, and besides a couple other reasons why its not ALWAYs better to go with static, its cheap.
When my camp buys our climbing program a spool I cut it into all 22's, with maybe a 56' and a 8.5' as well. The long and short ones are for those times when its just easier to use a longer or shorter piece of webbing then extending or shortening a 22'.
22' is a good length because its managable, take 6 22's if you want, youll have more than enough webbing to set up a couple climbs, even far anchors, etc.
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ptone
Sep 1, 2003, 6:11 PM
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webbing is static.
(static for us just means no stretch)
...but I could be wrong--
Does anyone know a situation where it would be better or safer to use dynamic rope vs static cord or webbing etc for an anchor or a rap point?
thanks
p
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boz84
Sep 1, 2003, 7:26 PM
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When I said static, i thought it was pretty obvious I meant static rope. No one refers to cordolettes or webing as static, although static rope is generally called just that: static.
Regardless, no I can't think of any reason why you'd use dynamic for an anchor, the aditional lstretch maybe could cause it to unequalise, thus putting too much stress on a point in the anchor. Although I could be wrong on this, ive never heard of people using static for that purpose.
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redpoint73
Sep 1, 2003, 10:16 PM
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In reply to: I can't think of any reason why you'd use dynamic for an anchor
Plenty of people use old dynamic ropes that they won't lead on anymore for TR anchors. Especially if you don't climb often enough in this type of situation (TR at areas with anchors far from edge of cliff) to warrent buying static line. I've not noticed a big effect on equalization due to elongation. Maybe if the different strands were significantly different in length. I still don't see why it would be a big deal. More important to worry about the angle of the anchors, how sound they are, etc.
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boz84
Sep 1, 2003, 10:59 PM
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In reply to: In reply to: I can't think of any reason why you'd use dynamic for an anchor More important to worry about the angle of the anchors, how sound they are, etc.
True, these are far more important than the negligible possible increase in unequalization caused by a dynamic rope. I was merely stating that I had never heard of people using dynamic for TR anchors, I was never told it could be done, and I gave one possible reason why i thought so.
But yes, you do make sense.
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ptone
Sep 1, 2003, 11:15 PM
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Sorry--I know generally 'static' refers to rope when used as a noun, but webbing and slings and all that are all static in nature, and everyone I know refers to them as static as well, when talking about climbing apps.
I an see how it would seem to be safer on tr, cause falls are short etc but IMO I think even just taking for rest and lowering and all that would cause a significant amount of rubbing throughout the anchor sysetem if the main lines were dynamic.
The repetitive sawing from a bit of stretch in an anchor line could easily damage a rope.
This is especially true if the anchors are far from the top, as the length of the rope from the anchors to the equalized point would be longer, meaning even more stretch.
Static whatever (ie sling, webolette, cordolette, rope etc) doesn't stretch like that and would greatly reduce that risk.
Just a couple more pennies for the kitty...
Peace,
p
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redpoint73
Sep 1, 2003, 11:22 PM
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In reply to: I think even just taking for rest and lowering and all that would cause a significant amount of rubbing throughout the anchor sysetem if the main lines were dynamic. The repetitive sawing from a bit of stretch in an anchor line could easily damage a rope. This is especially true if the anchors are far from the top, as the length of the rope from the anchors to the equalized point would be longer, meaning even more stretch.
Not really. Like I said, it is fairly common to use a dynamic rope. There does not seem to be a whole lot of stretch. You're likely not using a whole 165 foot rope. Plus, body weight is being divided amongst 2-3 strands. So for instance, if you take a 180 lb. person, divide that weight by three 40 or 50 foot strands, thats not a heck of a lot of stretch.
Of course, it will depend on how sharp the rock is, how the anchor is placed, etc. As always, check your anchors often.
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